private void Start()
{
if (computeShader == null)
{
throw new System.InvalidOperationException("Compute shader not set!");
}
if (_instance != null)
{
throw new System.InvalidOperationException("AtmosphereScatteringLutManager already exists!");
}
_instance = this;
AtmLutHelper.Init(computeShader);
CameraVolumeHelper.Init(computeShader);
for (int i = 0; i < pingPongUpdaters.Length; i++)
{
pingPongUpdaters[i] = new ProgressiveLutUpdater(null, lutConfig, this);
pingPongUpdaters[i].name = "Updater " + i;
}
//Quickly complete two set luts.
for (int i = 1; i <= 2; i++)
{
pingPongUpdaters[i].atmConfigToUse = atmosphereConfig;
var t = pingPongUpdaters[i].UpdateCoroutine();
while (t.MoveNext())
{
;
}
}
UpdateSkyboxMaterial(pingPongUpdaters[1], pingPongUpdaters[2]);
KickOffUpdater(pingPongUpdaters[0]);
}
//Generate camera volume texture.
private void OnPreRender()
{
if (RenderSettings.sun == null)
{
return;
}
// get four corners of camera frustom in world space
// bottom left
_FrustumCorners[0] = camera.ViewportToWorldPoint(new Vector3(0, 0, camera.farClipPlane));
// bottom right
_FrustumCorners[1] = camera.ViewportToWorldPoint(new Vector3(1, 0, camera.farClipPlane));
// top left
_FrustumCorners[2] = camera.ViewportToWorldPoint(new Vector3(0, 1, camera.farClipPlane));
// top right
_FrustumCorners[3] = camera.ViewportToWorldPoint(new Vector3(1, 1, camera.farClipPlane));
//Render camera volume texture.
var projection_matrix = GL.GetGPUProjectionMatrix(camera.projectionMatrix, false);
CameraVolumeHelper.CreateCameraAlignedVolumeTexture(ref transmittanceVolume, ref scatteringVolume, volumeTexSize);
CameraVolumeHelper.UpdateCameraVolume(
transmittanceVolume,
scatteringVolume,
volumeTexSize,
transform.position,
-RenderSettings.sun.transform.forward,
_FrustumCorners,
new Vector2(camera.nearClipPlane, camera.farClipPlane)
);
//Set it.
Shader.SetGlobalTexture("_CameraVolumeTransmittance", transmittanceVolume);
Shader.SetGlobalTexture("_CameraVolumeScattering", scatteringVolume);
var vp_matrix = projection_matrix * camera.worldToCameraMatrix;
Shader.SetGlobalMatrix("_Camera_VP", vp_matrix);
}
